Acquisitions and Divestitures - WideOpenWest, Inc. (Details) - USD ($) $ in Millions	1 Months Ended
Dec. 31, 2017	Aug. 31, 2017
WideOpenWest, Inc.
Business Acquisition [Line Items]
Business acquisition consideration	$ 226	$ 275

Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

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